Microfluidic devices are used in particular in order to manipulate liquids.
The technical publication M. Unger et al., Science 2000, page 288, paragraphs 113 to 116, for example, discloses a microfluidic device in the form of a microfluidic compression valve, which is produced from polydimethylsiloxane.
WO 2009/149986 A1 furthermore discloses a microfluidic compression valve and a method for its production. The compression valve comprises three substrates, the third substrate being arranged between the first and second substrates and consisting of an elastic material. Furthermore, the first substrate adjoins the third substrate and has at least one first recess on the side which adjoins the third substrate. The second substrate likewise adjoins the third substrate and has a second recess on the side which adjoins the third substrate. The first and second recesses are arranged at least partially opposite one another.
US 2010/0018584 A1 discloses a microfluidic system, comprising a piezoelectric actuator with which pressure can be exerted on a wall of a channel conveying fluid. When the piezoelectric actuator is operated, the wall of the microfluidic channel is deformed and the flow of the fluid can be controlled, or influenced.
US 2005/0205816 A1 discloses a pneumatically actuable microfluidic valve for use in laminated plastic fluidic structures. The microfluidic valve comprises a supply channel and a discharge channel, which are closable with a common membrane. The membrane can furthermore be moved into a recess, and a pressure can be applied to the recess by means of a further channel. If the pressure of the fluid in the supply channel is greater than the pressure in the recess, then the membrane is moved into the recess and liquid can flow from the supply channel into the discharge channel. If the pressure in the recess is increased so that it exceeds the pressure of the fluid in the supply channel, the membrane closes the supply channel and the discharge channel and no further liquid can flow from the supply channel into the discharge channel.
Lastly, US 2009/0166203 A1 discloses a microchip for capillary electrophoresis. The microchip comprises a supply channel and a separation channel, which are configured to receive a sample which is provided by a sample source. The sample source is arranged at one end of the separation channel. The supply channel and the separation channel form a T-junction. The microchip furthermore comprises a first valve, which is arranged next to the T-junction, and a separation channel and a second valve, which is arranged at the T-junction. The second valve is a two-way valve. When the second valve is closed in a vertical direction, the first and second ends of the separation channel are not in direct fluidic connection. When the second valve is closed in a horizontal direction, there is no fluidic connection between the first end/second end of the separation channel and the supply channel. Between the first end of the supply channel and the first end of the separation channel, however, there is a fluidic connection. Similarly, there is likewise a fluidic connection between the first end of the supply channel and the second end of the separation channel.